// MATTER · ELEMENT 77 / 118atoms.no/elements
Ir77
Iridium
Ir·Z 77·Transition Metal·192.2·⭕ 9A · E Minor
▸ The reading
interpretive · artThe thin iridium spike in the K-Pg clay layer is how we know an asteroid ended the dinosaurs — the metal is rare in crust but common in meteorites, so the anomaly was a signature. Most corrosion-resistant metal known; spark plugs spend it a millimetre at a time. The element that testified about extinction.
The science below is cited as science; the symbolic layers are flagged as interactive art.
⚜ Periodic Frequency
9AE Minor
a seat struck in brass — testimony, not prediction
the seat has its own room on ⭕ THE OVAL TABLE — tap the code
▸ The lenses
▸ Discovery
Smithson Tennant — co-discovered with osmium in the same platinum ore residue · England · 1803
▸ Stellar origin
r-process (neutron-star mergers)Built by rapid neutron capture in the most extreme cosmic environments. The K-Pg boundary clay's iridium enrichment is the smoking-gun fingerprint of the asteroid that killed the dinosaurs.
▸ Reactivity
Most corrosion-resistant metal knownResists every single acid and aqua regia. The 'iris' name refers to the rainbow of colors its compounds produce in different oxidation states.
▸ Applications
- Spark-plug electrodes (long-life)
- Crucibles for crystal growth (silicon, oxide single crystals)
- Standard kilogram alloy (platinum-iridium, until 2019)
- K-Pg boundary geological tracer
▸ Curiosity
Spike of iridium in the K-Pg clay layer is what proved an asteroid killed the dinosaurs — Ir is rare in Earth's crust but enriched in meteorites.
▸ Related readings
a resonance drawn between readings — not a claim that they share an origin.
Group 9RhRhodiumMtMeitnerium
Period 6OsOsmiumPtPlatinum
d-blockOsOsmiumPtPlatinum
Adjacent ZOsOsmiumPtPlatinum